I don't know if you're screwed or not, but don't worry.
You'll know soon enough.
I don't know if I'm in the same position as you, but I'll assume that you're in a better position than me. Same as you, about a month left, I haven't written more than about a sentence in any lessons for the past year and I haven't even done a minute of revision, literally no exaggeration. Not sure about your situation, but this is distressing for my school and parents as I am "Extremely Intelligent", predicted A*'s in most subjects, and A's in the remainders. I plan to revise a few days before exams, as I am allergic to any form of hard work. Living by the philosophies of 1: Do it on the day and 2: Do the bare minimum have served me well in the past but...
I guess we'll all know whether we did the right thing within the next 50 days or so...
By the way I think I will get a good haul of A's and A*'s in every subject, however, I'm set in an extremely difficult position to achieve what I want in the three Sciences, as we have already done the coursework for each and I was asleep for most of it so 25% of Science is a C for me. I now can't achieve A*'s in these, which is distressing for my Physics in particular, and need very high scores in order to get A's, which is what I want in Physics and Biology.
Good luck. If you're in the same position as me I suppose you will need it. (That isn't meant to be disconcerting. And don't be an idiot like me. Do the hard work. Even though I literally can't)